ON MONDAY, July 6, as Xinhua News Agency revised the official death toll from riots in far-western Xinjiang province from three to 156, I was looking for any moderate, rational and well-informed Chinese citizen to report their views on why Uighur and Han Chinese were tearing each other apart.

I was unanimously directed to an ethnic Uighur economist in Beijing, Ilham Tohti. But I was too late. Earlier that day Nur Bekri, Governor of Xinjiang, officially the Xinjiang Uyghur Autonomous Region, had blamed Tohti's website, Uighur Online (www.uighurbiz.net), together with a Kashgar website and the exiled Uighur leader Rebiya Kadeer for instigating the appalling violence.

Tohti had known his days of freedom were numbered since March, when he had criticised Bekri's obsession with the "fierce struggle" with "separatism" in Xinjiang.

In May, Tohti had told Radio Free Asia's Uighur service: "What I have encountered at this time is typical … I am a legal Beijing resident, and by law I should not be interrogated by Xinjiang police officials, but it has happened. This shows how long the local authorities' reach is. They accused me of separatism. But is demanding implementation of the autonomy law separatism?"

Tohti's blog was shut down in China. For a while it continued to host his comments on an American server. This is part of Tohti's final blog entry, on Tuesday, July 7: "Even if we say that Uighur Online and outsiders stirred things up — stirred what up? People can think for themselves. If everything was working so well, why did so many people suddenly come out and riot?"

I caught a plane from Beijing to Urumqi on the Monday night and never got through to Tohti. But Radio Free Asia's Uighur service did, on Tuesday, July 7. This is his last interview: "They are calling me now, and I have to go. I may be out of touch for some time. I wasn't involved in anything, but I am not safe. The police are calling me."

Unable to speak with Tohti, I emailed questions to outside authorities, such as the respected China economist Calla Wiemer. She replied on July 7: "The first thing I have to tell you is that for six years since I wrote that chapter I have not been able to get a visa to get into China."

The thoughtful answer that followed was later expanded into an online article, which is blocked in China (www.feer.com/politics/2009/july58/all-eyes-on-xinjiang).

The book Wiemer was referring to was Xinjiang: China's Muslim Borderland, edited by Frederick Starr.

Other Xinjiang experts who had contributed to that book gave diverse but similarly thoughtful replies."We simply don't know enough — there haven't been more than one or two foreign scholars working on these political questions, and they've had problems with access," wrote James Millward in answer to my email. "Most of the established US scholars on Xinjiang have been denied or given trouble on visas for the past 5 years: Millward, Gladney, Toops, Bovingdon, Dautcher etc."

These people and a few courageous Chinese analysts like Tohti are constrained either in their access to information or their freedom to speak. Says Millward: "The implicit policy since before the Olympics of treating Uighurs as potentially disloyal, potential terrorists, anti-Chinese, has stoked racist or chauvinist feelings among Han Chinese. This is in stark contrast to the previous PRC policy of 'unity of the nationalities'."

Things were moving too fast in China for me and perhaps anyone else to keep up.

On the night of Tuesday, July 7, I learned that Stern Hu, Rio Tinto's iron ore chief in Shanghai, and three of his Chinese staff had disappeared and their offices had been raided. The next day, the Australian Government confirmed The Age story and added that he had been detained by China's Ministry of State Security — probably the same organisation that had just taken Tohti. I never found an opportunity to report that on that Wednesday, Beijing authorities had moved to shut down Gongmeng, or Open Constitution Initiative, the only Chinese organisation to have published a broad and independent analysis on the root causes of last year's widespread violence in Tibet.

I have given little credence to the view that the Communist Party is unpopular in China and may lose its hold on the country.

But since the Tibet riots of March last year, the Chinese Communist Party has been acting as if its grip on power is fragile and illegitimate. Each time the Party panics, it increases its security settings and further alienates those with grievances inside China and adds to the friction with the outside world. At each step, it hands more power to those who have contributed most to the underlying problems.